Aptamer-based electrochemical biosensor for interferon gamma detection.

ABSTRACT: In this paper, we describe the development of an electrochemical DNA aptamer-based biosensor for detection of interferon (IFN)-?. A DNA hairpin containing IFN-?-binding aptamer was thiolated, conjugated with methylene blue (MB) redox tag, and immobilized on a gold electrode by self-assembly. Binding of IFN-? caused the aptamer hairpin to unfold, pushing MB redox molecules away from the electrode and decreasing electron-transfer efficiency. The change in redox current was quantified using square wave voltammetry (SWV) and was found to be highly sensitive to IFN-? concentration. The limit of detection for optimized biosensor was 0.06 nM with linear response extending to 10 nM. This aptasensor was specific to IFN-? in the presence of overabundant serum proteins. Importantly, the same aptasensor could be regenerated by disrupting aptamer-IFN-? complex in urea buffer and reused multiple times. Unlike standard sandwich immunoassays, the aptasensor described here allowed one to detect IFN-? binding directly without the need for multiple washing steps and reagents. An electrochemical biosensor for simple and sensitive detection of IFN-? demonstrated in this paper will have future applications in immunology, cancer research, and infectious disease monitoring.

SUBMITTER: Liu Y 

PROVIDER: S-EPMC2948235 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature